This application claims the priority benefit under 35 U.S.C. § 119 of Japanese Patent Application No. 2005-352191 filed on Dec. 6, 2005, which is hereby incorporated in its entirety by reference.
1. Field
The presently disclosed subject matter relates to a lamp system for a vehicle, and more particularly relates to a configuration of a lamp system for a vehicle that uses LEDs for the lamp's light source.
2. Description of the Related Art
FIGS. 3, and 4 show an example of a stop lamp 91 for a conventional vehicle lamp which is configured to change a turn-on pattern configuration. When a driver starts to depress a brake pedal 90 as shown in FIG. 3, a turn-on portion 91a appears as a narrow area at the center of the stop lamp 91 which includes LEDs arranged as a matrix, for example, as shown in FIG. 4.
When the driver further depresses the brake pedal 90, the number of LEDs which are turned on increases in proportion to the depressing force, resulting in an increase of the turn-on area 91a of the stop lamp 91. Thus, a driver of a following vehicle can recognize that the brake is applied harder on the lead vehicle based on the increased light emitting area of the stop lamps of the lead vehicle.
Then, if the driver of the lead vehicle further depresses the brake pedal 90, almost the entire surface of the stop lamp 91 emits light to form the turn-on area 91a, and the driver of the following vehicle can easily understand that the lead vehicle is in a full braking state, which allows the following driver to take corresponding measures such as application of full braking or the like. (See, Japanese Unexamined Patent Publication (Kokai) No. H01-197141, for example.)
Furthermore, there is proposed a turn signal lamp which turns on as a bright and dark stripe pattern, and the bright and dark stripe pattern moves as a vehicle makes a turn to more clearly notify a following vehicle and the like of the turn direction of the lead vehicle.
However, in the above-described conventional configurations, the stop lamp 91, for example, is intended to improve the brake light display for more clarity to a third person. Therefore, in a normal traveling state, the driver of the lead vehicle behaves as the driver of the following vehicle expects such as starting to depress the brake pedal 90 at a proper position according to a traffic signal at an intersection.
Thus, if an unexpected operation such an emergency braking is necessary, according to the conventional art devices, the light emitting area is increased as the depressed stroke of the brake pedal 90 increases, the mechanical travel speed of the brake pedal 90 remains the same, and there is thus generated a slight delay until the stop lamp 91 entirely turns on even if LED lamps, which have a fast response, are used as a light source.
Moreover, it is still necessary to consider whether the intended behaviors of the lead vehicle are fully understood by other vehicles, namely, whether communication is sufficient by means of lamps such as tail lamps, stop lamps, turn signal lamps, and backup lamps, which are presently equipped on a vehicle. Further, design of vehicle lamps has become stale as viewed by a following vehicle.